Looks like they don't intend to operate flights in their own right. From Flight
Mesa Air Group on 2 March announced a conditional agreement with London-based Gramercy Associates to launch a joint venture to operate Mesa’s Bombardier CRJ900 aircraft on passenger or cargo routes in Europe by the end of 2021.
The Phoenix-based parent company of Mesa Airlines would apply for a new air operator’s certificate to qualify for capacity purchase agreements or ACMI deals with carriers in Europe. Mesa would own 49% of the partnership with Gramercy, whose managing director is Tony Davis, the former chief executive of both Singapore-based Tiger Airways and the now-defunct UK carrier Bmibaby
https://www.flightglobal.com/strateg...142709.article